Cutting machine



Sept. 5, 1939.

s. SEG/M CUTTING MACHINE Filed Jan. 3l, 1936 3 Sheets-Sheet 1 Sept. 5,1939.

s. SEG-Al.

CUTTING MACHINE 3 Sheets-Sheet 2 Filed Jan. 31, 1936 INVENTOR ATTORNEY ASept. 5, 1939. s. sEGAL CUTTING MACHINE Sheets-Shea?l 5 Filed Jan. 31,1956 INVENTOR I ATTORNEY Patented Sept. 5, 1939 UNITED STATES PATENTOFFICE 7 Claims.

My invention relates to a cloth cutting machine having a reciprocableblade and improved means for sharpening the reciprocable blade. In clothcutting machines of the type utilizing a vertically reciprocable bladedilculty has been experienced so far as I am aware to properly sharpenthe blade while in its holder or guard. Although attempts were madehitherto to sharpen the reciprocable knife while secured in its holderthe cutting edge produced was of such character as to be inadequate forheavy duty and would not stand up for any appreciable periods of timeduring use. Accordingly the present invention has as a primary object toprovide in a cloth cutting machine vertically displaceableintermittently actuated vibratory sharpening means for its elongatedreciprocable blade adapted to alternately process or grind oppositebeveled faces of the blade to form a sharp edge substantiallycoextensive with the length of the blade even though the latter is inassembled relation with its vertical guard.

The invention has' as another object to utilize an oscillator havingfreely mounted and rotatable grinding wheels straddling the reciprocableblade, and means for actuating the oscillator for periodically andalternately moving the grinding wheels against beveled faces of theblade during relatively rapid reciprocation of the latter.

The invention comprehends as a further object the provision of means forsharpening the lowest vertical part of the edge of the blade, duringreciprocation thereofv and controlled means for sharpening the lowerhorizontal edge ofthe blade v during such reciprocation.

The invention contemplates as a further object the provision of a clothcutting machine characterized in that a conveniently controlled clutchis utilized to operatively interconnect a prime mover with transmissionmeans for rotating a double threaded screw whereby a carriage isreciprocably actuated for alternately lowering and raising sharpeningmeans straddling the reciprocable blade.

The invention has as further object the provision ofa clo-th cuttingmachine of the character alluded to, in which the double threadedscrewis operatively associated with means for intermittently andperiodically actuating a swiveled or pivoted oscillatable support freelyand rotatably sustaining the grinding or sharpening wheels straddlingthe reciprocable blade.

The invention also consists in certain newand useful features ofconstruction and combination of parts hereinafter set forth and claimedand as to other objects, advantages, the mode of its operation andmanner of its organization, these inter alia, may be better understoodby referring to the detailed description when considered with theaccompanying drawings in which:

Fig. 1 is a side View of the cloth cutting machine according to myinvention and showing its supporting base thereof partly in section.

Fig. 2 is a front view of Fig. 1.

Fig. 3 is a fragmentary and side view of Fig. 2. 10

Fig. 4 is a fragmentary and enlarged View of Fig. 1, illustrating theoscillatable sharpening means in position to process the lower verticalend of the reciprocable blade.

Fig. 5 is a sectional view taken on the line 5-5 l5 of Fig. 1.

Fig. 6 is a sectional view taken on the line 6 6 of Fig. 2, illustratingthe vibrator or oscillator, in a position-where the left grinding wheelis against the edge of the reciprocable blade.

Fig. 7 is a Viewl similar to Fig. 6, showing the oscillator in a neutral'position with the grinding wheels thereof straddling the blade andspaced therefrom.

Fig. 8 is a view similar to Fig. 6, however, show- 25 ing the rightgrinding wheel of the oscillator against the blade.

Fig. 9 is a sectional view taken on the line 9-9 of Fig. 2.

Fig. 10 is a sectional view taken on the line 30 III-IIJ of` Fig. 2.

Fig. 11 is a section taken along the line I I-I I of Fig. 2, showing asectional view of the reciprocable carriage operatively interconnectingthe double threaded screw and slidable sleeve for reciprocablydisplacing theY oscillator supporting arm and Y Fig. 12 is a view takenon the line I2--I2 of Fig. 11, illustrating a fragmentary portion of thedouble threaded driven screw.

Fig. 13 is a side view of the cutting blade.

Fig. 13A is a viewon the line I3A--I3A of Fig. 13.

Fig. 14 is an enlarged sectional view of one of the grinding .wheelsshown mounted on its arm of the oscillator.

Fig. 15 illustrates the pivoted or swiveled connection for theoscillator taken on the line I5-I 5 of Fig. 3 and Fig. 16 is a plan viewof the presser foot taken 50 on the line Iii-I6 of Fig. 1.

The cloth cutting machine, according to the invention, comprises a baseI0, a vertical channeled blade guard or .holder I I integral with alaterally and rearwardly extending arm I2 to 55 'front channeled shoe 46and iiXedly secured to whichis appropriately secured leg I3 dependingfrom casing of the prime mover or motor I4. .Also secured to arm l2 is ablock I5 on which the lower part of the annual rim vI6 of the casing isxedly retained.

Extending laterally from block l is a suitable handle I8 for bodilymoving the machine relative to a supporting surface I9. Associated withthe top part of the motor casing is a pair of upstanding posts 28electrically connected to the windings of the prime mover or motor I4.These posts are adapted to removably receive a plug or socket 2lappropriately connected to a source of electrical potential. Tofaciiltate lifting the machine and carrying the latter from-'place toi`place, annular hand I6 of the casing of the prime mover is provided witha T shaped handle'22.

Fixedly attached to the shaft 2.3of theprime.

mover is a relatively heavy counter balancing..

crank arm 24 having at one end thereof la forwardly extending pin 25 onwhich eye 26 Vof connectingrod'2'1 is svviveled while the lower end ofthe latter is operatively connected to the reciprocable cross head,generally denoted 28, having its rear portion slidably and verticallyguided in groove 29 of the shoe or track 3l)` attached to plate 3l whichin turn is appropriately secured tothe depending leg I3 of the motorcasing. k

The cross head 28 includes a depending gear32 carrying blade clampingmeans comprising ahead 3`3, a shank 34, a washer or collar35 and anadjustable nut 3,6. The spaced tines 31 of the upper bifurcated part ofthe cloth cutting blade 38 straddle shank 34 and the` spaced tines 31are brought against ear 32 of the cross head by head 33 upon theadjustment of the clamping nut 36.

The elongated blade is provided with a plurality of perforations 39,arrangedin staggered fashion, vertically disposed beveled faces 39 todeiine the vertical cutting edge 48, and lower beveled facesV 4I to formthe inclined cutting edge 42. f

A'lheblade isslidably guided -in an elongated vertical striation or gap43 formed by a pair of closely spaced metal leaves or bearings 44 in theform of elongated stripsfxedly retained in the rigid channeled guard orholder II.

With thesocket 2l Iattached to posts20, power to the motor or primemover may be suppliedby operating the( swingable handle lor switch 45which is directly connected in the 4motor Circuit and may eithermakeorbreak the latter as is well understood.VV

Where the electrical circuit to the motor is completed the cross head 28will be vertically reciprocated and consequentlythe blade will besimilarly .reciprocated relative to the guide I I'. Associated withtherear shoe 30 is a companion the latter is a bracket or frame generallyIdesignated 41. Shoes 30 and 46 form complementary vertical members forreciprocably guiding cross head 28. Specifically, however, bracket orsupport 41 comprises a vertically disposedrear wall 48 xedly althoughremovably secured'to the shoe 46 by screws 49. The one piece ,bracketl41also includes a transverse side wall 5U integral withrear vertical wall48 andthe spaced upper and lower forwardly projecting shelves 5I andYk,eningsupporting. `means gand. of oscillating the..v

- cated 54, that is, its larger end 55 is journalled in rear wall 48while forward end 56 is reduced and journalled in bearing 53 mounted onan expanded portion 56 overhanging transverse wall 50.

Stub shaft 54 is provided with a worm 51 adapted to mesh or interlockwith a complementary worm gear 58 to which is connected the companionbeveled gear 59. In other words, if the worm gear 58 is rotated, beveledgear 59 will be bodily rotated in synchronism therewith.

If desired the beveledv gear 59 and worm gear 58 may be of one piece oreach may be made separately and suitably fused together. For purposes ofspecifications, however, the worm gear 58Y and beveled gear 59 are bothrotatably retained on a horizontal stub shaft 60 and therefore bothrotate in unison in respect thereto, the stub shaft 60 beingappropriately secured to the upper part of the transverse wall 50 of thebracket or frame 41.

According to my invention, worm shaft 54 may be slidably'moved towardsor away from the prime mover. observed that the reduced portion 56 ofthe slidable and rotatable shaft 54 is provided with an annular iiange6I forming with the forward end of the worm 51 spaced abutment wallswhen selectively actuated by a rotatable disc 62 interposedtherebetween. This disc 62 (Figs. 9 and 10) is rotatably carried on apin 63 secured to` an upper oset portion 64 of the elongated lever 65having its intermediate portion pivoted on the expanded shank 66 (Fig.2) of set screw 61 having its reduced inner portion 68 Xed to thetransverse wall 58 of the bracket.

In the normal operation of the machine when utilizedl for cutting clothor the like, the slidable and rotatable shaft 54 of course, isoperatively disconnected from the prime mover. In such relation, clutchor arm 69 xedly carried by theV enlarged portion 55 of this stub shaft54. is out of the path of travel or orbit of the driving pin 25'on whichthe upper part of the connecting ro'd 21 is swiveled. In other words,rotatable clutch 69 is free of pin'25 of the prime mover when themachine is to be used for cutting cloth.

Specifically, however, control lever 65 is manually shifted to bodilymove shaft 54 in respect to the prime mover. For this purpose, themanipulating handle 12 is utilized. This handle has its upper portionpivotally secured to transverse Wall 50 of the bracket and also carriesvan eccentrically mounted disc or cam 14 which cooperates with lever 65to pivot or tilt the .latter about shank 66 of set screw 61 fixed towall 58.

When control handle 12 is elevated or turned, cam 14 causes the upperoffset portion 64 of lever 65 to move forwardly or away from the primemover, that is, roller 62 abuts iiange 6I and consequently shaft 54 andits' worm 51 bodily and slidably move away from driving pin 25associated with.' the prime mover. Therefore clutch 69 is moved out ofthe path of pin 25 (Fig. V10). It follows that although vthe blade maybe reciprocated, the sharpening means for the bladeis disconnected fromthe prime mover.Y It will be In this connection, it will be noted,however,'that as the upper part of lever 75 V85 is moved away from theprime mover, the

lower part 15 thereof moves towards the prime mover and against thehelicoidal spring 16 having its rear end retained in the recess 11 andits forward end abutting the lower part 15 of lever 65 althoughencircling pin or post 18 carried by lower part 15.

If the manipulating handle 12 is rotated to point downwardly asindicated in Figs. 2 and 3, cam 14 moves away from or becomes free oflever 65 and consequently spring 16 expands thus automatically movinglower part 15 of lever 65 forwardly while its. upper offset portionmoves rearwardly. It follows that roller 62 is moved automaticallytowards the prime mover causing stub shaft 54 to be bodily and slidablyshifted towards pin 25. Hence clutch 69 is arranged in the orbit or pathof the driving pin 25, thus establishing .a driving connection betweenthe prime mover and the transmission comprising beveled gears 80 and 59,worm gear 58 and worm 51.

The horizontal beveled gear 80 is appropriately pinned or fixed to thevertically disposed elongated and hollow screw generally denoted 8|rotatably disposed in the upper and lower shelves 5I and 52 of thebracket in suitable bearings 82 and 83 respectively.

Interconnecting screw 8| and a vertically guided slidable sleeve 84 is areciprocable carriage, broadly designated 85, which includes a block 86closely conned in an opening 81 thereof. Block 86 is provided with-asingle tooth 83 constantly and slidably guided by .and Within an endlessdouble threaded groove, generally designated 39 which consists ofhelicoidal groove 96 for guiding tooth 88 downwardly and the helicoidaland communicating groove 9| for guiding tooth 88 upwardly, the companionupper ends and lower ends of the helicoidal grooves 90 and 9| beinginterconnected by a curved groove yas 92 shown schematically in Fig. 12and in dotted lines in Fig. 2. Hence a continuous but double threadedgroove is formed in the driven screw 8| and by reason of tooth 88 beingguided thereby, carriage 85 is driven in a rectilinear direction tocomplete a full down stroke and thereafter driven linearly but upwardlyto complete a full return stroke, that is, the carriage is reciprocatedduring rotation of the screw provided the clutch is operativelyconnected to the prime mover as hereinbefore described, it being noted,however, that flattened tooth 88 of the carriage is rmly retained withinthe double threaded screw 89 by a plate 93 held against the forward wallof the carriage by suitable fastening means 94.

Carriage 85 is held fixed with respect to the vertically slidable sleeve84 by the clamping bolt 95, and since the carriage is reciprocated byreason of the action of screw BI, it follows that sleeve 84 carried bythe carriage, in turn, will be reciprocated .although guided in thismovement by the elongated fixed spindle 96 retained against rotation byset screw 91 in the upper shelf 5I of the bracket.

Cylindrical spindle 96 guides reciprocable displacement of sleeve 84 andconsequently the latter is alternately projected and retracted on eachdown and up stroke respectively of the carriage.

Fixedly attached to the lower part of slidable sleeve 84 is an L shapedarm 98 which has a .horizontal and intermediate portion provided with abearing or bushing 99 rotatably guiding `the cylindrical elongated rod.|00 having a vertical key way IOI (Fig. 9) receiving key or lug |02fastened to hollow double threaded screw 8|. It follows therefore ifscrew 8| be rotated, the coupled or keyed rod |00 will becorrespondingly rotated in synchronism. It will be noted, however, thatL shaped arm 98 is provided with an upstanding hollow boss |03 which isrigidly secured to the lower portion 94 of the reciprocable sleeve 84 bythe clamping bolt |05 while lower shelf 52 of the bracket includes anappropriate guide bearing |06 closely surrounding sleeve 94 butpermitting longitudinal displacement thereof.

With clutch 69 connected to the driving pin 25 the double threaded screw8| will be rotated if shaft 23 of the prime mover is rotating. Itfollows therefore that shaft |00 which is coupled to screw 8| willlikewise be rotated and therefore cog or spider, broadly denoted, |06rigidly attached to the lower end of the driven shaft |00 iscorrespondingly rotated.

Spider |06 comprises three outwardly extending and similar teeth orvanes |01, |08 and |09, arranged one hundred and twenty degrees .apartfor periodically cooperating with inwardly and oppositely arrangedprojections or cams IIO, III integral with the swiveled oscillatorcomprising loop or ring II2 and an integrally connected fork orbifurcation I|3 comprising a pair of diverging arms I I4 and II5 facingtowards and straddling the reciprocable blade 38 retained in holder II.

Arms II4 and II5 each rotatably and slidably support a cylindrical shaftI|6 each appropriately holding at its inner end a sharpening or grindingCarborundum wheel 1I. More particularly each grinding wheel 1I isprovided with xed bearing or bushing IIS (Fig. 14) comprising a hollowcylindrical shank II9, a flange |20 and theflared flange I2! formed byupsetting shank II9. The flanges |29 and I2I (Figs. 6 and lll) togetherwith their shank I I9 have a friction and tight fit with the centralreduced and perforated portion of the bore of the grinding wheel whileits axle or shaft IIS is provided with an annular shoulder |I6 toprevent displacement of the bushing in one direction and the shaft HGincludes an upset wedge |22 to prevent displacement of the bushing in anopposite direction, the bushing having a relatively tight fit with itsshaft II6 and bodily rotates therewith but shaft II6 is slidablerelative to its supporting arm of the vibrator or oscillator and isprovided with head or stop |23 to prevent removal thereof.

More particularly oscillator or fork I I3 is provided with a fixedupstanding pin |24 which is rotatably supported in the bore |25extending through arm 98 and its upstanding boss |26. However, rotatablepin |24 (see Fig. I5) is provided with an annular groove |21 in whichthe inner end of shank |28 of set screw |29 is arranged. ln other words,shank |28 constitutes means for rotatably supporting pin |24 which isguided in bore |25 and consequently oscillator or vibrator II3 canswivel or pivot V'in respect to its support 98.

In Fig. '1, the grinding wheels 1I are in neutral position although cog|06 is rotating as indicated by the arrow. Further rotation of the cogin the same direction causes tooth |01 to strike cam IIO andconsequently oscillator IIS is bodily rotated or swung in a directioncorresponding to the direction of rotation of the cog and therefore armI I5 of the oscillator moves towards the blade while arm II4 moves awayfrom the blade. Therefore grinding wheel 1I which is carried by arm H5and'which is rotatablymounted on to shaft H6 moves against an adjacentbeveled edge of the blade 38 (Fig. 8) to process the latter until tooth.|01 of the cog leaves cam H0. Shortly thereafter tooth |08 of the cogstrikes cam or tooth |H of the oscillating fork H3, hence causing thelatter to bodily and horizontally swing or rotate in a direction counterto the rotation of the cog as indicated by the arrow in Fig. 6. Thusgrinding lwhe'eel 1| rotatably carried by arm H4 of the oscillator movesin contact with the opposite beveled face of the blade while thegrinding wheel of arm H15 moves away from the blade and such contactwith the blade will be maintained until tooth |08 leaves cam IH.

On' each revolution of cog |06 each tooth thereof causes the oscillatorH3 to swing in one direction and subsequently in an opposite direction.Hence where the cog is provided with three teeth as illustrated, theoscillator will complete three complete vibratory cycles for eachrevolution of the cog. A complete vibratory cycle for purposes ofdefinition may be said to comp-rise a throw of the oscillator in onedirectio-n to process one side of the blade plus a throw of theoscillator in an opposite direction to process the o-pposite side of theblade. Of course while a grinding wheel 1| comes in contact with thereciprocating blade, such wheel will be set in rotation to facilitatesharpening of the blade.

By the present invention, it is apparent that the cog constitutes meansfor periodically actuating the oscillator I I3, thereby permittingalternate and intermittent processing of opposite faces of the blade. Ifit is desired to increase the rate of vibration of the oscillator it iswithin the province of the invention to provide a cog having mo-re thanthree teeth. However, in practice and from experience it has beendiscovered that alternate impacts on the opposing faces of the knifeedge due to the operation of a three toothed cog of the type shownproduces the required cutting edge and further that such edge will standvup-for relatively long periods even though subjected to relativelyheavy work consisting of a multiplicity of layers of cloth or the like|30 (Fig. 1).

The present theory of sharpening a reciprocable blade by vibratory meansin a cloth cutting machine so far as I am aware constitutes' a distinctdeparture over the means for sharpening blades hitherto employed in thatthe former devices of the prior art for the same purposes hereindisclosed were concerned with .grinding means continuously in contactwith the edge of the blade during reciprocation thereof. Although acertain edge with these older devices was formed, such edge, it has beendiscovered, has a relatively short duration under actual workingVconditions and could not stand up under appreciable periods of time andinstead of cutting the work as desired, the cloth will tear.

According to the principle of sharpening blades herein disclosed, theblade although reciprocating is intermittently processed and alternatelyon opposite faces of the blade but in a relatively fast fashion wherebya cutting edge is provided of desiredstrength and having the necessarycutting qualities to penetrate a large bulk of cloth or other materialcomprising many superimposed layers.

Further in accordance with the present invention provision has been madefor keeping the blade relatively cool and lubricated althoughreciprocating rapidly during periods of. cutting or sharpening.V In thisconnection, it will be ob'- served, that apart from the staggeredlyarranged and spaced perforations 39 in the body of the blade, the latteralso includes inclined lubricant retaining grooves 3| disposed on theopposite faces of the body of the blade and each interconnecting with' apair of adjacent openings 33. These relatively narrow and shallowgrooves guide any lubricant dripping from the openings and serve toretain such lubricant where the latter is of the liquid type and ifdesired a graphite lubricant of the solid type may be employed inconnection with openings 39. Lubricant spilling from openings 39 andgrooves |3| lubricate the body of the blade as it reciprocably slides inits holder or guide I between the spaced leaves 44.

Slidably disposed and guided between the transverse wall 50 of thebracket 41 and a vertical track |33 which is secured to wall 50 is anadjustable square shaped rod |34 having its lower end rigidly secured inboss |35 carried by the cloth pressure foot |33 (Figs. 1 and 16)comprising spaced arms |31 and |38 dening a tapered slot |39 adapted topermit the passage of the reciprocable blade 38 into and throughstriation or slot |40 (Fig. l) of a disc |4| from which guard or holderupwardly extends. The presser foot |36 is provided with a refleXedhandle or ear |42 adapted to be grasped by the operator to slidablyadjust the presser foot in respect to the layers of cloth |30.

However, the cloth presser foot may be manually adjusted when thehorizontal brake arm |43 (Figs. 3 and 5) is released from vertical rod|34. The brake arm |43 has a flattened rear end pivotally connected to ashank of a set screw |44 carried by a crank arm |45 connected torotatable rod |46 (Figs. Sand 5) journalled in leg |3 of the motorcasing and the block 3| associated therewith. f

Control means for manipulating rockable rod |46 is in the form of alever |41 (Fig. 1) having one end pivoted in a slot |48 and on set screw|49 carried by rod |46. Lever |41 is normally retained in an elevatedposition by the free offset end |49 of a spring |50 having itsintermediate portion |5| coiled about rod |46, and its other end or arm|52 is retained in a groove |53 of a set screw |54 fastened to block 3|.

- When control lever |41 is depressed free portion |49 of spring |50 isalso depressed and consequently arm |52 thereof is flexed. However, iflever |41 is depressed, rod |46 is rotated or rocked, thereby causingcrank arm |45 to be correspondingly displaced. Thus brake arm |43 ismoved rearwardly and becomes free of the vertical and slidable rod |34of the presser foot which falls automatically tofcompress the severallayers of cloth mounted on base I0.

M Upon removal of manual pressure from control lever I41, arm |55 of thespring |50 loses its energy and automatically elevates lever |41. Hencethe b-rake arm |43 is rotated in a counterdirection and moves againstthe slidable and adjustable rod |34, holding the latter in a locked orset position. Y f

Appropriately journalled within the base I0 of the machine and belowdisc 4| whichrsupports guard or holder H, is a pair of blade sharpeningrollers |50 and |5|. Specically, however, each of these rollers -isrotatably carried in bearing blocks |52 and |53 (Figs. 1 and 2) slidablyguided in.channels |54 and v|55 in base I0 and these bearings areretained in their channels by an appropriate removable cover plate |56.

Cooperating with each slidable bearing |52 and |53 -is a helicoidalspring |51 which normally urges its bearing towards the center of knifereceiving'striation or slot |40. The object of rollers |56 and |5| is tosharpen the lower horizontal and slightly inclined edge 42 of the blade.Such edge is desired to overcome clogging of knife receiving slot |-40and to keep the latter clean during movements of the blade in guide I Torender sharpening rollers |50 and |5| ineffective, the latter may beseparated against the resistance of springs |51 by rotating spindle orshaft |6| (Figs. 1 and 2) for displacing cam |62 carried by the latter.Where the manipulating wheel |63 is grasped and rotated, shaft |6| isrotated, and consequently cam |62 is displaced, causing lugs |64 and |65depending from the slidable bearings |52 and |53 to spread apart.Subsequently, however, the ends |66 of the cam coact with lugs |64 and|65 holding these a predetermined distance apart and preventingdisplacement of the slidable bearings towards each other until rod |6|is again manipulated to release the widest portion of the cam from thedepending lugs. In their linear displacement lugs |64 and |65 are guidedb-y slots |61 in the removable cover plate |56.

Briely recapitulating the operation of the herein machine, to cut astack |30 of layers of cloth, the latter is placed on a` suitable tableand the handle |8 is grasped to move lip |68 of the base of the machineunder the stack |30, after which, control handle |41 is depressed. Thepresser foot |36 falls by gravity and onto the upper lever of the stack,thus holding the latter against the base of the machine. Downwarddisplacement of the presser foot is limited, however, by stop pin |1|which may strike the upper end of track |33 (Fig. 2). Of course wherethe machine is used for cutting purposes, the oscillatable means ||3supporting the rotatable grinding wheels 1| should be first arranged asto be near the top of the blade (Figs. l and 2). This may beaccomplished manually or automatically. In the iirst case, hand wheel 10associated with shaft 23 (Fig. 1) would be manually turned until thecarriage 85 is at the top of the screw 8|. In the second case, switch 45may be thrown to cut the prime mover in circuit and with the clutchthrown in with the prime mover, the latter is operated until thecarriage is at the top of the screw after which the clutch isdisconnected from the motor.

With the clutch 69 mechanically disconnected from the prime mover, thesharpening means 1| ineffective at the top of the blade, and the presserfoot holding the stack of cloth down, the switch 4| is thrown to closethe electrical circuit for the prime mover and the blade is caused toreciprocate. The operator then grasps handle I8 and bodily moves themachine on the supporting rollers |10 and into the work which is in partsupported by lip |68 of base I0 and subsequently guides thereciprocating blade along a guide line on the top layer of the work asis well understood.

When it is desired to sharpen the blade, the machine is removed from thestack of cloth, control lever |41 is depressed to release brake arm |43,thus permitting the presser foot |36 to fall to its lower position whichis controlled by the stop pin |1| (Fig. 3) striking the track or guide|33. In such case presser foot |36 would rest on base l0. Handle 12 isthen thrown downwardly, causing eccentric or cam 14 to shift lever 65for moving the clutch into engagement with driving pin 25. In suchrelation the clutch is continuously in the path of pin 25 of therelatively heavy crank 21 associated with the prime mover. Hence motionimparted by the prime mover is transmitted to the companion bevel .gears59 and 86. Therefore the double threaded screw 8| is set in rotation andcarriage 85 moves first downwardly and subsequently upwardly traversingthe entire length of the screw on each cycle of the carriage.

I f the carriage is reciprocated, sleeve 84 is also reciprocated andconsequently the oscillator supporting arm 98 is reciprocated. However,during this operation, shaft |00 is rotated and cog |66, causing theoscillator |3 to rock or swivel as previously pointed out. Hence thereciprocating blade is interruptedly or intermittently processed by thegrinding wheels. First one part of one face of the blade is processed.Subsequently another part of the opposite face of the blade is processedalthough the blade is reciprocating. Such cycle of sharpening iscontinued for a relatively brief period of time to form the requiredknife edge and thereafter the clutch is disconnected from the primemover. It should be noted, however, that during the interruptedsharpening operation, the lower vertical part of the blade is alsosharpened by wheels 1| (Fig. 4) and if the sharpening rollers |50 and|5| have been previously set by actuating thumb piece |63 to be closelydisposed, then the lower horizontal edge 42 of the blade is processedsince at the end of each downward stroke thereof during reciprocation itpasses through slot |40 and contacts the sharpening rollers |50 and |5|and if desired oscillator ||3 may be provided with a depending boss |80adapted to automatically abut and shift foot |36 against the resistancyof brake arm |43 on the first complete downward stroke of the blade anddispose said presser foot against base |0 to be out of the path of theoscillator on successive down strokes thereof.

As many changes could be made in the above construction and manyapparently widely different embodiments of the invention could bedevised without departing from the scope thereof, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

I claim:

1. In combination, a prime mover, a blade, means connected to said primemover for reciprocating said blade, a transmission, means fordisconnectably connecting said transmission to said prime mover, acarriage, driven means actuated by said transmission for reciprocatingsaid carriage, supporting means reciprocated by said carriage, anoscillator swingably sustained relative to said supporting means, a pairof grinding wheels straddling said blade and rotatably sustained by saidoscillator and means associated with said driven means and cooperatingwith said oscillator to alternately shift said grinding wheels into andout of contact with opposing faces of said blade during reciprocation ofsaid oscillator and said blade.

2. In combination, a prime mover, a blade, means connected to said primemover for reciprocating said blade, a transmission, clutch means fordisconnectably engaging said transmission with said prime mover, adouble threaded screw connected to said transmission, a carriageoperatively connected to said screw and reciprocated by the Vlatter uponrotation thereof, a displaceable member reciprocated by said carriage, asupport carried by said member, means swingable relative to said supportcomprising an oscillator, means associated with said screw for vibratingsaid oscillator, and grinding wheels rotatably mounted on saidoscillator and straddling said blade and adapted to impact opposingifaces of said blade during reciprocation of said carriage and bladeupon each cycle of vibration of said oscillator. t

3. In combination, a prime mover, a blade, means connected to said primemover for reciprocating said blade, a transmission, clutch means fordisconnectably engaging said transmission with said prime mover, adouble threaded screw connected to said transmission, a carriageoperatively connected to said screw and reciprocated by the latter uponrotation thereof, a slidable member reciprocated by said carriage, asupport carried by said member, an oscillator, vswingably associatedwith said support comprising spaced arms and spaced cam means; agrinding wheel rotatably sustained by each of said arms; and meanscomprising a spider bodily rotatable with said screw for severally andsuccessively actuating said cam means for alternately moving said armstowards and away from said blade during reciprocation of said blade andcarriage.`

4. In combination, a prime mover, a blade, means connected to said primemover for reciprocating said blade,V a transmission,` clutch means fordisconnectably engaging said transmission with said prime mover, adouble threaded screw connected to said transmission, a carriageoperatively connected to said screw and reciprocated by the latter uponrotation thereof, a slidable member reciprocated by said carriage, asupport carried by said member; an oscillator, swingably associated withsaid support, comprisingV a pair of spaced arms and a plurality of cams;a grinding wheel rotatably andslidably displaceable'relative to each ofsaid arms, and a spider rotated by said screw andrhaving a plurality ofteeth each adapted to severally and successively contact said cams ofsaid plurality for swinging said oscillator to permit the grinding wheelof one of said arms to contact one face of said blade duringreciprocation thereof and simultaneously move the grinding'wheel of theremaining arm of said pair away from, an opposite face of said blade.

5. In combination, a prime mover, a blade, means connected to said primemover for reciprocating said blade, a transmission, clutch means fordisconnectably engaging said transmission with said prime mover, a screwconnected to said transmission, a carriage operatively connected to saidscrew and reciprocated by the latter upon rotation thereof, a slidablemember reciprocated by said carriage, a support carried by said member,an oscillator, swingably associated with said support, comprising a pairof spaced arms and a plurality of cams, a grinding wheel rotatablysupported by each of said arms, a spider rotated by said screw andhaving a plurality of teeth each adapted to severally and successivelyactuate said cams of said plurality on each cycle of vibration of saidoscillator and wherein each cycle consists of first swinging saidoscillator in one direction to permit one of said grinding wheels tocontact one face of said blade during reciprocation thereof andsimultaneously moving the remaining grinding wheel away from theopposite face of said blade, and Subsequently swinging said oscillatorin an opposite direction to permit the grinding wheel previously out ofcontact with said blade to contact said opposite face of said bladeduring reciprocation of said blade and simultaneously moving thegrinding wheel previously in contact with said reciprocating blade awayfrom and out of contact with said rst mentioned face of said blade.

6. In a cutting machine of the class described, a prime mover, a base, aguard interposed between said base and prime mover, a blade slidablyguided within said guard, means associated with the prime mover forreciprocating said blade, slidable presser means, a support operativelyconnected to said prime mover and reciprocated by the latter,oscillatable sharpening carrying means carried by said support,controlled brake means for resisting displacement of said presser means,and means associated with said oscillatable sharpening carrying meansfor moving said presser means downwardly towards said base against theresistance of said brake means on the initial downward stroke of saidreciprocable support.

7. In a cutting machine of the class described, a prime mover, a base, aguard interposed between said base and prime mover, a blade slidablyguided within said guard, means associated with said prime mover forreciprocating said blade, slidable presser means, a support operativelyconnected to said prime mover and reciprocated by the latter, anoscillator carried by said support, rotatable sharpening wheels carriedby said oscillator and adapted to straddle the fore part of said bladeduring reciprocation of the latter, controlled brake means for resistingdisplacement of said presser means, and means carried by said pressermeans adapted to be contacted by said oscillator for moving said pressermeans downwardly towards said base against the resistance of said brakemeans on the initial downward stroke of said reciprocable support.

SAMUEL SEGAL.

